世界上“第二难”的简单几何题（图）

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BDE = 110 - AED in line 6 you have 150 – BED = 150 – 110 + AED which implies BED=110-AED From the picture, you know that BDE and BED are two different angles. They may not be equal. You need to prove in line 6 150 – BED = 150 – 110 + AEDwww.ddhw.com